This invention relates to a shield connector for being mounted on a printed circuit board.
Generally, a shield connector for being mounted on a printed circuit board has a metallic shield shell covering an outer surface of a resin-made connector housing receiving terminals therein. The shield shell is electrically connected to a ground pattern on the printed circuit board, thereby electromagnetically shielding connecting portions of the connector terminals (see, for example, JP-A-2002-170640).
FIGS. 4 to 7 show such a related shield connector M1 for a printed circuit board, and FIG. 4 is a perspective view showing the appearance of the shield connector M1, FIG. 5 is a longitudinal cross-sectional view thereof, FIG. 6 is a perspective view showing a condition in which an outer shield shell is to be attached to an outer periphery of an outer housing, FIG. 7A is a side view of the shield connector, and FIG. 7B is a cross-sectional view taken along the line VIIb-VIIb of FIG. 7A, which is explanatory of problems with the shield connector.
As shown in FIG. 5, this shield connector M1 includes terminals 10 each bent into an L-shape (when viewed from the side), a resin-made inner housing 20 having the terminals 10 press-fitted therein (or insert molded therein), a metallic inner shield shell 30 of a tubular shape covering an outer periphery of the inner housing 20, the resin-made outer housing (corresponding to a connector housing) 140 having the inner shield shell 30 mounted therein, and the outer shield shell 150 covering the outer surface of the outer housing 140.
As shown in FIGS. 4 to 7, the outer housing 140 has a rectangular parallelepiped outer shape, and has a lower face 43 adapted to be placed on an upper surface of a printed circuit board (not shown). A fitting opening 47 (into which a mating connector is fitted) is formed in the front side of the outer housing 140, and a fitting lock portion 46 is formed on an inner surface of a front end of the fitting opening 47. When a housing of the mating connector is fitted into the outer housing 140, the fitting lock portion 46 locks this mating housing.
The terminal 10 is of the male type, and is press-fitted in the inner housing 20. The terminal 10 includes an electrical contact portion 11 whose distal end portion projects from the inner housing 20, and a proximal end portion of the terminal 10 is bent into an L-shape to form a lead portion 12 for connection to a circuit pattern on the printed circuit board (not shown). The lead portion 12 projects downwardly beyond the lower face 43 of the outer housing 140.
The inner shield shell 30 is mounted within the outer housing 140, with its tubular front portion 31 projecting into the fitting opening 47. The inner shield shell 30 is insulated from the terminals 10 by the inner housing 20 provided within the inner shield shell 30. A rear end portion of the inner shield shell 30 is disposed to cover the lead portions 12 of the terminals 10, and a ground terminal 32 for connection to a ground pattern on the printed circuit board is formed at the rear end of the inner shield shell 30.
The outer shield shell 150 has a generally inverted U-shape when viewed from the front side, and includes a top plate 51 covering an top surface 41 of the outer housing 140, a pair of right and left side plates 52 respectively covering right and left side surface 42 of the outer housing 140, and a rear plate 53 covering the rear side of the outer housing 140. The outer shield shell 150 is slid from the rear side of the outer housing 140, and is attached to the outer surface of the outer housing 140. A ground line connection portion 55 for forming a ground line is formed on the top plate 51 of the outer shield shell 150. Ground terminals 54a are formed respectively at lower edges of the right and left side plates 52, and also a ground terminal 54b is formed at a lower edge of the rear plate 53, these ground terminals 54a and 54b being adapted to be connected to the ground pattern on the printed circuit board. Retaining projecting piece portions 54c of the split type for retaining engagement with the printed circuit board are formed respectively at lower edges of rear portions of the right and left side plates 52.
A pair of slits 158 are formed respectively in the right and left side plates 52 of the outer shield shell 150 and extend in the back and forth direction, and also a pair of ribs 148 are formed respectively on the right and left side surface 42 of the outer housing 140 and extend in the back and forth direction. When slidingly attaching the outer shield shell 150 to the outer housing 140 from the rear side, the slits 158 are fitted respectively to the ribs 148 to guide the sliding movement of the outer shield shell 150.
When the shield connector M1 is assembled, the inner housing 20 having the terminals 10 press-fitted therein (or insert molded therein) is prepared, and the inner shield shell 30 is mounted on the inner housing 20, and then the inner shield shell 30 having the inner housing 20 received therein is inserted into the outer housing 140. Then, the outer shield shell 150 is slid onto the outer housing 140 from the rear side, and is attached thereto. At this time, the ribs 148 are fitted respectively in the slits 158, thereby guiding the sliding movement of the outer shield shell 150. When the outer shield shell 150 is completely attached to the outer housing 140, the mutually-fitted slits 158 and ribs 148 hold the outer shield shell 150 against upward movement, that is, prevent the outer shield shell 150 from being disengaged upwardly from the outer housing 140.
Thereafter, the shield connector M1 is placed on the printed circuit board, and the ground terminals 54a and 54b of the outer shield shell 150 are connected to the ground pattern on the printed circuit board, and the lead portions 12 of the terminals 10 are connected to the circuit pattern on the printed circuit board, thus completing the mounting of the shield connector M1 on the printed circuit board.
In the conventional shield connector M1 shown in FIGS. 4 to 7, the slits 158 are formed respectively in the right and left side plates 52 of the outer shield shell 150, and therefore there is a problem that the stiffness of the outer shield shell 150 against deformation is small. Namely, the slits 158 extend respectively from the front edges of the right and left side plates 52 of the outer shield shell 150, and therefore the right and left side plates 52 are liable to be resiliently bent or deformed outwardly (as indicated by arrows A) in the right-left direction away from each other as shown in FIG. 7B. When this opening deformation occurs and the slits 158 are disengaged from the respective ribs 148, there is a possibility that the outer shield shell 150 is disengaged upwardly (in a direction of arrow B) from the outer housing 140. Therefore, the handling of the assembled shield connector M1 requires attention until it is mounted on the printed circuit board, and this is cumbersome. In addition, since the opening-like slits 158 are formed in the outer shield shell 150, an electromagnetically-shielding area of this outer shield shell 150 is reduced by an amount corresponding to the areas of the slits. Therefore, the shielding ability is deteriorated, and an anti-noise performance is deteriorated, and as a result it is worried that a high-speed transmission performance and others may be affected.